Apparatus for needle-punching a web

ABSTRACT

The apparatus comprises a table which is formed with perforations and adapted to support a web as it is continuously advanced. Needle beam means are spaced above said table. Needle board means are carried by said needle beam means. A multiplicity of needles are carried by said needle board means and depend therefrom and are in register with said perforations. Push rods are connected to said needle beam means and vertically guided by push rod guides and vertically reciprocable to impart to said needle beam means an up and down motion causing said needles to move into and out of said perforations. A plurality of connecting rods are connected to said driving eccentric shaft means. A plurality of rocker levers are provided, each of which has a fulcrum and is pivoted to one of said push rods and one of said connecting rods. Adjusting means are provided, which are adapted to adjust said fulcrum of each of said rocker levers in height during the rotation of said driving eccentric shaft means.

United States Patent [191 Obenaus [111 3,849,845 51 Nov. 26, 1974 APPARATUS FOR NEEDLE-PUNCHING A Primary ExaminerLouis K. Rimrodt Attorney, Agent, or Firm-Kurt Kelman [57] ABSTRACT The apparatus comprises a table which is formed with perforations and adapted to support a web as it is continuously advanced. Needle beam means are spaced above said table. Needle board means are carried by said needle beam means. A multiplicity of needles are carried by said needle board means and depend there from and are in register with said perforations. Push rods are connected to said needle beam means and vertically guided by push rod guides and vertically reciprocable to impart to said needle beam means an up and down motion causing said needles to move into and out of said perforations. A plurality of connecting rods are connected to said driving eccentric shaft means. A plurality of rocker levers are provided, each of which has a fulcrum and is pivoted to one of said push rods and one of said connecting rods. Adjusting means are provided, which are adapted to adjust said fulcrum of each of said rocker levers in height during the rotation of said driving eccentric shaft means.

4 Claims, 2 Drawing Figures the web is moved continuously on a perforated table,

said needle beam being moved up and down by vertically guided push rods, which are connected by connecting rods to a driving eccentric shaft, which may consist, if desired, of shaft sections, which are coupled to each other.

In the previously known needle-punching apparatus the connecting rods are directly coupled to the push rods so that the stroke and the stroke position of the needle-carrying structure cannot be varied. Because the table which supports the web is usually not vertically adjusted during the travel of the web, it is impossible to interrupt the needle-punching operation and to vary the depth of penetration of the needles. Because the known apparatus is composed of modular units, it

is advantageous'for needle-punching extremely wide non-woven webs. On the other hand, it cannot be used to provide a web with needle-punched patterns.

To provide the web with a needle-punched pattern, it is also known to arrange the needles in the needle board in various patterns and to operate the means for driving the needle-carrying structure and the means for advancing the web in alternation so that intervals in which there is no needle-punching operation are left between the needle-punching periods. This results in the formation of a needle-punched pattern. The continual starting and stopping of the means for driving the needle-carrying structure and for advancing the web is undesired because it involves running-up and slowingdown times and a high energy consumption. Besides, that known arrangement enables only a small variation as regards the transfer of the pattern of the needles on the needle boards to the web.

In another known apparatus for needle-punching fiber webs or the like, each section of the needle beam is connected to a separate, double-acting pneumatic or hydraulic actuator for moving the section up and down and these actuators are synchronized. Depending on the application of pressure, the timing of the reversals and the interval between successive reversals, the piston stroke and with it the needle stroke can be varied in adaptation to the respective web, and the dead center positions of the pistons and with them the stroke position of the needle beam-can also be varied. It has been found, however, that an exact synchronism of all actuators cannot be achieved and it is not possible in practice to select different dead center positions of the pistons with the required accuracy.

It is an object of the invention so to improve the needle-punching apparatus of the kind described first hereinbefore that the same is simple in structure and reliable in operationand enables a continuous change of push rods by rocker levers and the. fulcrums of said rocker levers are adjustable in height during the operation of the driving eccentric shaft. When the fulcrums of the rocker levers are raised or lowered, the needle beam will perform its up and down motion on both sides of a higher or lower middle position so that the stroke position is changed as desired. Depending on the extent to which the fulcrums are raised, the needles do no longer contact the web at all or the depth of penetration is reduced so that the patterns produced by the needles are spaced apart accordingly because the web travels continuously, or the changed depth of penetration results in a change of the appearance of the patterns on the web. The fulcrums of the rocker levers can be adjusted in height quickly and continuously with any desired technical means because it is required only to raise or lower a part. It is essential in this connection that there is no need to stop the means for driving the needle beam and the means for advancing the web.

A particularly desirable arrangement for adjusting the fulcrums of the rocker levers in height will be obtained if the fulcrums of the rocker levers are carried by connecting rods, which are connected to a switching eccentric shaft, which is parallel to the driving eccentric shaft. In that case it will be sufficient to rotate the switching eccentric shaft. This can be accomplished by means of a pneumatic or hydraulic actuator, a mechanical transmission, or by electric means. The switching shaft can be rotationally oscillated to a certain extent or the switching shaft may rotate continuously if this is permitted or required in view of the desired pattern.

If the needle beam is divided into several sections and the driving eccentric shaft consists of shaft sections which are coupled for joint rotation, the switching eccentric shaft will also be divided into switching shaft sections, which are associated with respective shaft sections of the driving eccentric shaft and which are either coupled for joint rotation orare independently rotatable. It is significant that self-contained units can be arranged one beside the other and, where the switching shaft sections are independently rotatable, the web can be provided with differently patterned longitudinal stripes.

An embodiment of the invention is shown by way of example on the accompanying drawing, in which FIG. 1 is a vertical sectional view showing the essential parts of a needle-punching apparatus and FIG. 2 is a top plan yiew showing said parts with the housing cover removed.

A housing 1 forms vertical guides 2 for two push rods 3 and is provided with a cover 4. A driving eccentric shaft 5 and a switching eccentric shaft 6 are mounted in said housing and extend parallel one beside the other. A needle beam section 7 of a needle is suspended from the push rods 3 and carries needle boards 8. Connecting rods 9 are connected to the driving eccentric shaft 5 and are connected to the push rods 3 by rocker levers 10, which are provided with fulcrums 11 carried by connecting rods 12, which areconnected to the switching eccentric shaft 6. A pressure fluid actuator 14 is connected by a crank arm 13 to the switching eccentric shaft 6 and is operable to rotationally oscillate the switching eccentric shaft. Instead of the actuator 14, any desired other mechanical or electric drive means may be used for this purpose. The driving eccentric shaft 5 is driven by an electric motor 15.

The rotation of the driving eccentric shaft 5 results in an up and down motion of the rocker levers 10 so that the needle beam section 7 performs a corresponding up and down motion. When the switching eccentric shaft 6 is rotated, the fulcrums of the rocker levers will be raised or lowered so that the stroke position of the needle beam section 7 will be changed while the rotation of the driving eccentric shaft 5 is continued. The needles of the needle boards 8 penetrate to a larger or smaller depth the web which is advanced below them or remain clear of the web.

In case of a wider web, a plurality of the apparatus which has been described are used as units, which are secured one beside the other to continuous beams. In that case the driving eccentric shaft 5 and the switching eccentric shaft 6 of each unit constitute shaft sections and the sections of each shaft are connected for joint rotation by couplings 16. Alternatively, the couplings between the switching eccentric shaft sections 6 of the several units could be omitted and said switching shaft sections could be rotated independently of each other.

What is claimed is:

1. Apparatus for needle-punching a continuously advancing web, which comprises a table formed with perforations and adapted to support said web as it is continuously advanced, needle beam means spaced above said table,

needle board means carried by said needle beam means,

a multiplicity of needles which are carried by said needle board means and depend therefrom and are in register with said perforations,

vertical push rod guides,

push rods connected to said needle beam means and vertically guided by said push rod guides and vertically reciprocable to impart to said needle beam means an up and down motion causing said needles to move into and out of said perforations,

driving eccentric shaft means,

a plurality of connecting rods connected to said driving eccentric shaft means,

a plurality of rocker levers, each of which has a fulcrum and is pivoted to one of said push rods and one of said connecting rods, and

adjusting means adapted to adjust said fulcrum of each of said rocker levers in height during the rotation of said driving eccentric shaft means.

2. Apparatus as set forth in claim 1, in which said adjusting means comprise switching eccentric shaft means extending parallel to said driving eccentric shaft means and a plurality of switching connecting rods, each of which connects said fulcrum of one of said rocker levers to said switching eccentric shaft means.

3. Apparatus as set forth in claim 1, in which said needle beam means consist of a plurality of needle beam sections,

a plurality of said push rods are connected to each of said beam sections, and

said driving eccentric shaft means consist of a plurality of driving eccentric shaft sections which are coupled for joint rotation.

4. Apparatus as set forth in claim 3, in which said adjusting means comprise switching eccentric shaft means extending parallel to said driving eccentric shaft means and consisting of a plurality of switching eccentric shaft sections, each of which is associated with one of said beam sections and one of said driving eccentric shaft sec- 

1. Apparatus for needle-punching a continuously advancing web, which comprises a table formed with perforations and adapted to support said web as it is continuously advanced, needle beam means spaced above said table, needle board means carried by said needle beam means, a multiplicity of needles which are carried by said needle board means and depend therefrom and are in register with said perforations, vertical push rod guides, push rods connected to said needle beam means and vertically guided by said push rod guides and vertically reciprocable to impart to said needle beam means an up and down motion causing said needles to move into and out of said perforations, driving eccentric shaft means, a plurality of connecting rods connected to said driving eccentric shaft means, a plurality of rocker levers, each of which has a fulcrum and is pivoted to one of said push rods and one of said connecting rods, and adjusting means adapted to adjust said fulcrum of each of said rocker levers in height during the rotation of said driving eccentric shaft means.
 2. Apparatus as set forth in claim 1, in which said adjusting means comprise switching eccentric shaft means extending parallel to said driving eccentric shaft means and a plurality of switching connecting rods, each of which connects said fulcrum of one of said rocker levers to said switching eccentric shaft means.
 3. Apparatus as set forth in claim 1, in which said needle beam means consist of a plurality of needle beam sections, a plurality of said push rods are connected to each of said beam sections, and said driving eccentric shaft means consist of a plurality of driving eccentric shaft sections which are coupled for joint rotation.
 4. Apparatus as set forth in claim 3, in which said adjusting means comprise switching eccentric shaft means extending parallel to said driving eccentric shaft means and consisting of a plurality of switching eccentric shaft sections, each of which is associated with one of said beam sections and one of said driving eccentric shaft sections. 